태양 전지용 CuInSe2 단결정 박막 성장과 태양 전지로의 응용

Abstract

The stoichiometric mixture of evaporating materials for the CuInSe2 single crystal thin film was prepared from horizontal furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal CuInSe2, it was found tetragonal structure whose lattice constant a0 and c0 were 5.783 Å and 11.621 Å, respectively. To obtain the CuInSe2 single crystal thin film, CuInSe2 mixed crystal was deposited on throughly etched GaAs(100) by the HWE(Hot Wall Epitaxy) system. The source and substrate temperature were 620 ℃ and 410 ℃ respectively. The crystalline structure of CuInSe2 single crystal thin film was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of Van der Pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by impurity scattering in the temperature range 30 K to 100 K and by lattice scattering in the temperature range 100 K to 293 K. The temperature dependence of the energy band gap of the CuInSe2 obtained from the absorption spectra was well described by the Varshni's relation, Eg(T)=1.1851 eV-(8.99×10-4 eV/K)T2/(T+153 K). The open-circuit voltage, short current density, fill factor ,and conversion efficiency of n-CdS/p-CuGaSe2 heterojunction solar cells under 80 mW/cm2 illumination were found to be 0.51V, 29.3 mA/cm2, 0.76 and 14.3 %, respectively